International Journal of Agriculture, Environment and Biotechnology Citation: IAEB: 15(04): 851-860, December 2022 DOI: 10.30954/0974-1712.04.2022.9 How to cite this article: Hamalton, T. and Sahana, K.S. (2022). An Overview of the Adaptive Variations in Mangroves. Int. J. Ag. Env. Biotech., 15(04): 851-860. Source of Support: None; Conflict of Interest: None ASSOCIATION FOR AGRICULTURE ENVIRONMENT AND BIOTECHNOLOGY A A E B An Overview of the Adaptive Variations in Mangroves Tresa Hamalton* and Sahana, K.S. Institute of Wood Science and Technology, Bangalore, Karnataka, India *Corresponding author: d.tresa@gmail.com (ORCID ID: 0000-0002-2427-0174) Paper No. 1064 Received: 27-08-2022 Revised: 03-11-2022 Accepted: 30-11-2022 ABSTRACT Mangrove species grow on saline soils of the tropical and subtropical coasts, which are permanently or periodically fooded. The mangroves are halophytes having certain traits which help them to survive in difering levels of salinity, drought, inundation and extreme temperatures. They can remarkably normalize ion homeostasis in brackish conditions by salt secretion, ultra fltration and ion appropriation. These plants have diferent developmental, physiological and anatomical adaptations as compared to a normal tree, which allow their survival in high stress habitat. This review is focused on those features of the mangroves that help them to adjust and grow extensively in the saline rich coastal regions, which make mangrove species physiologically diferent from other trees. HIGHLIGHTS m Mangroves possess various unique physiological features that allow them to withstand harsh environmental conditions. Keywords: Mangroves, salt stress, physiological adaptations, harsh environment The word ‘mangrove’ refers to woody plants of intertidal forest communities. Mangroves are known to grow in over 123 countries and occur in geo-morphologically similar location with highly varying foristic compositions depending on the salinity atributes of the region (Tomlinson 1986; Hamilton and Casey, 2016). The estimated global cover of mangroves is about 1, 50,000 km 2 . Regionally, over 40% of the global mangroves are in the south and south-east Asian region. India is bestowed with 45.8% of the mangrove cover within this south-east Asian territory (Spalding et al. 2010). Indian mangrove habitats are classifed into three major groups viz., Deltaic (east coast), Non-Deltaic (west coast) and Island (Andaman Nicobar and Lakshadweep). In India, the mangrove cover is 57% in the east coast, 30% in west coast, and 13% is within the Andaman Nicobar and Lakshadweep islands. Sundarbans, West Bengal in the east coast and Gujarat in the west coast are the major regions in India, comprising 43% and 23% of the total mangrove cover, respectively. ‘Mangrove community’ is the general term for diferentiating the plant assemblage from the individual mangrove species. The mangrove trees have enthralled physiologists for many decades (Saenger 2002; ICFRE, 2020). All mangrove plants have special adaptations that allow them to survive in their harsh environment, though there are contradictory views regarding whether the mangroves are obligate or facultative halophytes. Morphological and physiological characteristics for adaptation include aerial roots, viviparous embryos, tidal dispersal of propagules, rapid rates of canopy production, absence of growth rings, wood with narrow densely distributed vessels, highly efcient nutrient retention mechanism, the ability to cope with salt, and to maintain water and carbon balance (Naskar and Palit 2014; Nizam et al. REVIEW ARTICLE